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<div class="titlepage"><div><div><h4 class="title">
<a name="boost_asio.overview.windows.object_handle"></a><a class="link" href="object_handle.html" title="Object HANDLEs">Object HANDLEs</a>
</h4></div></div></div>
<p>
          Boost.Asio provides Windows-specific classes that permit asynchronous wait
          operations to be performed on HANDLEs to kernel objects of the following
          types:
        </p>
<div class="itemizedlist"><ul class="itemizedlist" type="disc">
<li class="listitem">
              Change notification
            </li>
<li class="listitem">
              Console input
            </li>
<li class="listitem">
              Event
            </li>
<li class="listitem">
              Memory resource notification
            </li>
<li class="listitem">
              Process
            </li>
<li class="listitem">
              Semaphore
            </li>
<li class="listitem">
              Thread
            </li>
<li class="listitem">
              Waitable timer
            </li>
</ul></div>
<p>
          For example, to perform asynchronous operations on an event, the following
          object may be created:
        </p>
<pre class="programlisting"><span class="identifier">HANDLE</span> <span class="identifier">handle</span> <span class="special">=</span> <span class="special">::</span><span class="identifier">CreateEvent</span><span class="special">(...);</span>
<span class="identifier">windows</span><span class="special">::</span><span class="identifier">object_handle</span> <span class="identifier">file</span><span class="special">(</span><span class="identifier">my_io_service</span><span class="special">,</span> <span class="identifier">handle</span><span class="special">);</span>
</pre>
<p>
          The <code class="computeroutput"><span class="identifier">wait</span><span class="special">()</span></code>
          and <code class="computeroutput"><span class="identifier">async_wait</span><span class="special">()</span></code>
          member functions may then be used to wait until the kernel object is signalled.
        </p>
<h6>
<a name="boost_asio.overview.windows.object_handle.h0"></a>
          <span><a name="boost_asio.overview.windows.object_handle.see_also"></a></span><a class="link" href="object_handle.html#boost_asio.overview.windows.object_handle.see_also">See Also</a>
        </h6>
<p>
          <a class="link" href="../../reference/windows__object_handle.html" title="windows::object_handle">windows::object_handle</a>,
          <a class="link" href="../../reference/windows__basic_object_handle.html" title="windows::basic_object_handle">windows::basic_object_handle</a>,
          <a class="link" href="../../reference/windows__object_handle_service.html" title="windows::object_handle_service">windows::object_handle_service</a>.
        </p>
<h6>
<a name="boost_asio.overview.windows.object_handle.h1"></a>
          <span><a name="boost_asio.overview.windows.object_handle.notes"></a></span><a class="link" href="object_handle.html#boost_asio.overview.windows.object_handle.notes">Notes</a>
        </h6>
<p>
          Windows object <code class="computeroutput"><span class="identifier">HANDLE</span></code>s
          are only available at compile time when targeting Windows. Programs may
          test for the macro <code class="computeroutput"><span class="identifier">BOOST_ASIO_HAS_WINDOWS_OBJECT_HANDLE</span></code>
          to determine whether they are supported.
        </p>
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<td align="right"><div class="copyright-footer">Copyright &#169; 2003-2012 Christopher M. Kohlhoff<p>
        Distributed under the Boost Software License, Version 1.0. (See accompanying
        file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
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